Genetic exchange of fimbrial alleles exemplifies the adaptive virulence strategy of Porphyromonas gingivalis.
Genetic exchange of fimbrial alleles exemplifies the adaptive virulence strategy of Porphyromonas gingivalis.
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DOI：
10.1371/journal.pone.0091696
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Tribble GD
中科院分区：
文献类型：
--
作者：
Kerr JE;Abramian JR;Dao DH;Rigney TW;Fritz J;Pham T;Gay I;Parthasarathy K;Wang BY;Zhang W;Tribble GD
牙龈卟啉单胞菌是一种革兰氏阴性厌氧菌，是人类口腔微生物组的成员，并且是慢性牙周炎（牙龈的炎性疾病）发展中的“关键”病原体。牙龈卟啉单胞菌是一种遗传多样性物种，并且能够通过天然感受态和接合在菌株之间交换染色体DNA。在这项研究中，我们调查的作用，水平DNA转移作为一个适应性的过程，以修改行为，使用的主要菌毛作为我们的模型系统，由于他们的关键作用，介导与宿主环境的相互作用。我们表明，牙龈卟啉单胞菌是能够交换菌毛等位基因类型I和IV到四个不同的菌株背景，通过自然的能力。在所有重组体中，我们检测到整个fimA等位基因的完全交换，并且交换速率在不同菌株背景之间变化。此外，菌毛遗传位点的其他区域内的基因交换被确定。为了测量这些等位基因交换的生物学意义，我们比较了在等基因背景中的三种fimA基因型，菌株ATCC 33277。我们证明了菌毛等位基因类型的交换导致了深刻的表型变化，包括菌毛的数量，膜起泡，自动聚集和其他与毒性相关的表型。I型等位基因与III型或IV型等位基因的替换导致牙龈成纤维细胞相对于同基因亲本菌株的侵袭增加。虽然已知遗传变异性会影响宿主-微生物组相互作用，但这是第一项定量评估泛基因组云中交换基因的适应性影响的研究。这是重要的，因为它提出了一个潜在的机制，机会致病菌可以获得必要的性状，以修改宿主-微生物相互作用。
Porphyromonas gingivalis is a gram–negative anaerobic bacterium, a member of the human oral microbiome, and a proposed “keystone” pathogen in the development of chronic periodontitis, an inflammatory disease of the gingiva. P. gingivalis is a genetically diverse species, and is able to exchange chromosomal DNA between strains by natural competence and conjugation. In this study, we investigate the role of horizontal DNA transfer as an adaptive process to modify behavior, using the major fimbriae as our model system, due to their critical role in mediating interactions with the host environment. We show that P. gingivalis is able to exchange fimbrial allele types I and IV into four distinct strain backgrounds via natural competence. In all recombinants, we detected a complete exchange of the entire fimA allele, and the rate of exchange varies between the different strain backgrounds. In addition, gene exchange within other regions of the fimbrial genetic locus was identified. To measure the biological implications of these allele swaps we compared three genotypes of fimA in an isogenic background, strain ATCC 33277. We demonstrate that exchange of fimbrial allele type results in profound phenotypic changes, including the quantity of fimbriae elaborated, membrane blebbing, auto-aggregation and other virulence-associated phenotypes. Replacement of the type I allele with either the type III or IV allele resulted in increased invasion of gingival fibroblast cells relative to the isogenic parent strain. While genetic variability is known to impact host-microbiome interactions, this is the first study to quantitatively assess the adaptive effect of exchanging genes within the pan genome cloud. This is significant as it presents a potential mechanism by which opportunistic pathogens may acquire the traits necessary to modify host-microbial interactions.
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Keystone-Pathogen假设。
DOI：
10.1038/nrmicro2873
发表时间：
2012-10
期刊：
Nature reviews. Microbiology
影响因子：
--
作者：
通讯作者：
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影响因子：
4.3
作者：
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影响因子：
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通讯作者：
Schmidt, H
影响因子：
3.1
作者：
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通讯作者：
Lamont, RJ
影响因子：
9.4
作者：
Amano, A;Nakagawa, I;Hamada, S
通讯作者：
Hamada, S